Figure 1

Expressions of p16^INK4a, CRX and Ki67 in a representative RB case from RC group (100x). a. HE staining showed well-differentiated RC cells with typical fleurettes surrounded by moderately differentiated tumor cells; b. p16^INK4a was negative in the RC region, but positive in the surrounding tumor cells. A magnified image (insert) shows the transition zone between the RC and the tumor cells; c. CRX expression displayed the opposite pattern to that of p16^INK4a, being strongly positive in RC region but negative in the surrounding area; d. Ki67 expression was similar to that of p16^INK4a, with barely positive cells in RC region. All inserts, 200x.